Yesterday, a bracelet recipe dropped from a regular mob (archer) in prospector's crafting instance.
As for the chance of boos drop, well, if a former chance was 1/10000 and now it's ten times more chance, it's still only 1/1000 chance for a drop, so your 36 tries are insignificant.
Anyway, I would try do farm it at all. It's a good item, but any decent player can do any content without it as well as with it.
Warden(85), Minstrel(85), Rune-Keeper(85), Burglar(85), Captain(85), Hunter(85)